The invention applies in particular to pneumatic drilling machines which are used in aircraft construction.
The first phase of the cycle is generally a phase for advancing and simultaneously rotating the spindle, and the second phase is a phase for retracting and simultaneously rotating the spindle.
The device for controlling the operation of the machine allows the operation of a machine of this type to be stopped automatically once a cycle has been carried out.
In this manner, when a user has installed a plurality of these machines on a support frame and has initiated the operation thereof, the machines stop automatically without any need for specific intervention in respect of any of them.
In this manner, the noise caused by the machines being operated is limited. Furthermore, the pollution produced by the air loaded with lubricant which escapes from the motors of machines of this type is also limited.
In machines of the above-mentioned type, the device for controlling the operation comprises elements of the pneumatic circuit which are dedicated to controlling the closure of the motor supply valve at the end of the retraction phase of the cycle.
It should be noted that the structure of the control device is relatively complex and expensive, in particular because of these dedicated pneumatic elements.
One objective of the invention is to overcome this problem by providing a machine of the above-mentioned type which has a simpler structure and is less expensive.